This project will construct a high resolution genetic map of human chromosome with an average resolution of 1-2 centimorgans. To achieve this goal, we will identify simple sequence repeat containing clones from chromosome 13 enriched plasmid and cosmid libraries by hybridization to poly (dA-dC)/poly (dT-dG) and other simple sequence probes. These (CA)2 containing clones will be sequenced to obtained unique flanking sequences, primers for amplification by the PCR method will be selected, and each marker will be tested for length polymorphism. We will ultimately identify 100-150 di-, tri-, and tetranucleotide repeat polymorphisms with a PIC of 0.7 or greater. We will roughly assign physical location of each marker by hybridization to a YAC library and by in situ hybridization to human metaphase chromosomes. Approximately located markers will be placed on the genetic map by linkage analysis in the extended C.E.P.H. panel. C.E.P.H. families will be typed by PCR amplifica tion of polymorphic segments and resolution of alleles on standard sequencing gels followed by autoradiography. Use of multiplex PCR and simultaneousx analysis of multiple reactions will be developed to speed genotyping. Automated genotyping using the ABI automated sequencing system will be explored. Gene-centromere distances for markers flanking the centromere will be estimated using a panel of Type II human ovarian teratomas.